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1.
Small ; 20(26): e2308527, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38221686

RESUMO

Flexible hydroelectric generators (HEGs) are promising self-powered devices that spontaneously derive electrical power from moisture. However, achieving the desired compatibility between a continuous operating voltage and superior current density remains a significant challenge. Herein, a textile-based van der Waals heterostructure is rationally designed between conductive 1T phase tungsten disulfide@carbonized silk (1T-WS2@CSilk) and carbon black@cotton (CB@Cotton) fabrics with an asymmetric distribution of oxygen-containing functional groups, which enhances the proton concentration gradients toward high-performance wearable HEGs. The vertically staggered 1T-WS2 nanosheet arrays on the CSilk fabric provide abundant hydrophilic nanochannels for rapid carrier transport. Furthermore, the moisture-induced primary battery formed between the active aluminum (Al) electrode and the conductive textiles introduces the desired electric field to facilitate charge separation and compensate for the decreased streaming potential. These devices exhibit a power density of 21.6 µW cm-2, an open-circuit voltage (Voc) of 0.65 V sustained for over 10 000 s, and a current density of 0.17 mA cm-2. This performance makes them capable of supplying power to commercial electronics and human respiratory monitoring. This study presents a promising strategy for the refined design of wearable electronics.

2.
Acta Pharmacol Sin ; 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38689095

RESUMO

Endothelial senescence, aging-related inflammation, and mitochondrial dysfunction are prominent features of vascular aging and contribute to the development of aging-associated vascular disease. Accumulating evidence indicates that DNA damage occurs in aging vascular cells, especially in endothelial cells (ECs). However, the mechanism of EC senescence has not been completely elucidated, and so far, there is no specific drug in the clinic to treat EC senescence and vascular aging. Here we show that various aging stimuli induce nuclear DNA and mitochondrial damage in ECs, thus facilitating the release of cytoplasmic free DNA (cfDNA), which activates the DNA-sensing adapter protein STING. STING activation led to a senescence-associated secretory phenotype (SASP), thereby releasing pro-aging cytokines and cfDNA to further exacerbate mitochondrial damage and EC senescence, thus forming a vicious circle, all of which can be suppressed by STING knockdown or inhibition. Using next-generation RNA sequencing, we demonstrate that STING activation stimulates, whereas STING inhibition disrupts pathways associated with cell senescence and SASP. In vivo studies unravel that endothelial-specific Sting deficiency alleviates aging-related endothelial inflammation and mitochondrial dysfunction and prevents the development of atherosclerosis in mice. By screening FDA-approved vasoprotective drugs, we identified Cilostazol as a new STING inhibitor that attenuates aging-related endothelial inflammation both in vitro and in vivo. We demonstrated that Cilostazol significantly inhibited STING translocation from the ER to the Golgi apparatus during STING activation by targeting S162 and S243 residues of STING. These results disclose the deleterious effects of a cfDNA-STING-SASP-cfDNA vicious circle on EC senescence and atherogenesis and suggest that the STING pathway is a promising therapeutic target for vascular aging-related diseases. A proposed model illustrates the central role of STING in mediating a vicious circle of cfDNA-STING-SASP-cfDNA to aggravate age-related endothelial inflammation and mitochondrial damage.

3.
J Am Chem Soc ; 145(16): 9285-9291, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37040147

RESUMO

Organic hierarchical branch micro/nanostructures constituted by single crystals with inherent multichannel characteristics exhibit superior potential in regulating photon transmission for photonic circuits. However, organic branch micro/nanostructures with precise branch positions are extremely difficult to achieve due to the randomness of the nucleation process. Herein, by taking advantage of the dislocation stress field-impurity interaction that solute molecules deposit preferentially along the dislocation line, twinning deformation was introduced into microcrystals to induce oriented nucleation sites, and ultimately organic branch microstructures with controllable branch sites were fabricated. The growth mechanism of these controllable single crystals with an angle of 140° between trunk and branch is attributed to the low lattice mismatching ratio (η) of 4.8%. These as-prepared hierarchical branch single crystals with asymmetrical optical waveguide characteristics have been demonstrated as an optical logic gate with multiple input/out channels, which provides a route to command the nucleation sites and offers potential applications in the organic optoelectronics at the micro/nanoscale.

4.
Small ; 19(22): e2205833, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36876447

RESUMO

Thermochromic smart windows with rational modulation in indoor temperature and brightness draw considerable interest in reducing building energy consumption, which remains a huge challenge to meet the comfortable responsive temperature and the wide transmittance modulation range from visible to near-infrared (NIR) light for their practical application. Herein, a novel thermochromic Ni(II) organometallic of [(C2 H5 )2 NH2 ]2 NiCl4 for smart windows is rationally designed and synthesized via an inexpensive mechanochemistry method, which processes a low phase-transition temperature of 46.3 °C for the reversible color evolution from transparent to blue with a tunable visible transmittance from 90.5% to 72.1%. Furthermore, cesium tungsten bronze (CWO) and antimony tin oxide (ATO) with excellent NIR absorption in 750-1500 and 1500-2600 nm are introduced in the [(C2 H5 )2 NH2 ]2 NiCl4 -based smart windows, realizing a broadband sunlight modulation of a 27% visible light modulation and more than 90% of NIR shielding ability. Impressively, these smart windows demonstrate stable and reversible thermochromic cycles at room temperature. Compared with the conventional windows in the field tests, these smart windows can significantly reduce the indoor temperature by 16.1 °C, which is promising for next-generation energy-saving buildings.

5.
Sensors (Basel) ; 23(8)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37112267

RESUMO

Mobile payment services have been widely applied in our daily life, where users can conduct transactions in a convenient way. However, critical privacy concerns have arisen. Specifically, a risk of participating in a transaction is the disclosure of personal privacy. This might occur if, for example, the user pays for some special medicine, such as AIDS medicine or contraceptives. In this paper, we propose a mobile payment protocol that is suitable for mobile devices only with limited computing resources. In particular, the user in a transaction can confirm the identity of others in the same transaction while the user cannot show convincing evidence to prove that others also take part in the same transactions. We implement the proposed protocol and test its computation overhead. The experiment results corroborate that the proposed protocol is suitable for mobile devices with limited computing resources.

6.
BMC Bioinformatics ; 23(1): 470, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36348299

RESUMO

BACKGROUND: The expression changes of some proteins are associated with cancer progression, and can be used as biomarkers in cancer diagnosis. Automated systems have been frequently applied in the large-scale detection of protein biomarkers and have provided a valuable complement for wet-laboratory experiments. For example, our previous work used an immunohistochemical image-based machine learning classifier of protein subcellular locations to screen biomarker proteins that change locations in colon cancer tissues. The tool could recognize the location of biomarkers but did not consider the effect of protein expression level changes on the screening process. RESULTS: In this study, we built an automated classification model that recognizes protein expression levels in immunohistochemical images, and used the protein expression levels in combination with subcellular locations to screen cancer biomarkers. To minimize the effect of non-informative sections on the immunohistochemical images, we employed the representative image patches as input and applied a Wasserstein distance method to determine the number of patches. For the patches and the whole images, we compared the ability of color features, characteristic curve features, and deep convolutional neural network features to distinguish different levels of protein expression and employed deep learning and conventional classification models. Experimental results showed that the best classifier can achieve an accuracy of 73.72% and an F1-score of 0.6343. In the screening of protein biomarkers, the detection accuracy improved from 63.64 to 95.45% upon the incorporation of the protein expression changes. CONCLUSIONS: Machine learning can distinguish different protein expression levels and speed up their annotation in the future. Combining information on the expression patterns and subcellular locations of protein can improve the accuracy of automatic cancer biomarker screening. This work could be useful in discovering new cancer biomarkers for clinical diagnosis and research.


Assuntos
Biomarcadores Tumorais , Neoplasias , Imuno-Histoquímica , Redes Neurais de Computação , Aprendizado de Máquina , Proteínas , Neoplasias/diagnóstico
7.
Public Health Nutr ; : 1-12, 2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36138541

RESUMO

OBJECTIVE: The relationship of a diet low in fibre with mortality has not been evaluated. This study aims to assess the burden of non-communicable chronic diseases (NCD) attributable to a diet low in fibre globally from 1990 to 2019. DESIGN: All data were from the Global Burden of Disease (GBD) Study 2019, in which the mortality, disability-adjusted life-years (DALY) and years lived with disability (YLD) were estimated with Bayesian geospatial regression using data at global, regional and country level acquired from an extensively systematic review. SETTING: All data sourced from the GBD Study 2019. PARTICIPANTS: All age groups for both sexes. RESULTS: The age-standardised mortality rates (ASMR) declined in most GBD regions; however, in Southern sub-Saharan Africa, the ASMR increased from 4·07 (95 % uncertainty interval (UI) (2·08, 6·34)) to 4·60 (95 % UI (2·59, 6·90)), and in Central sub-Saharan Africa, the ASMR increased from 7·46 (95 % UI (3·64, 11·90)) to 9·34 (95 % UI (4·69, 15·25)). Uptrends were observed in the age-standardised YLD rates attributable to a diet low in fibre in a number of GBD regions. The burden caused by diabetes mellitus increased in Central Asia, Southern sub-Saharan Africa and Eastern Europe. CONCLUSIONS: The burdens of disease attributable to a diet low in fibre in Southern sub-Saharan Africa and Central sub-Saharan Africa and the age-standardised YLD rates in a number of GBD regions increased from 1990 to 2019. Therefore, greater efforts are needed to reduce the disease burden caused by a diet low in fibre.

8.
Angew Chem Int Ed Engl ; 61(22): e202117857, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35290693

RESUMO

Optical interconnects exhibit superior potential in the precise regulation of photon transmission for organic photonic circuits. However, the rational design of well-defined organic heterostructures toward active optoelectronics remains challenging. Herein, we designed organic branched heterostructures (OBHs) with accurate spatial organization for optical interconnection. Notably, the precise regulation of OBHs has been controllably achieved including the trunk morphologies and the branched microwire number. Significantly, these as-prepared OBHs inherently exhibit the multichannel coupling outputs and the excitation position-dependent waveguide characteristics, leading to various outcoupling signals with tunable intensity and emission colors. The optical interconnects are realized due to the occurrence of exciton conversion and photon propagation between branch and trunk at the heterojunction, benefiting the application possibilities of two-dimensional (2D) optical barcodes.

9.
Angew Chem Int Ed Engl ; 60(16): 9114-9119, 2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33538056

RESUMO

Near-infrared (NIR) organic solid-state lasers play an essential role in applications ranging from laser communication to infrared night vision, but progress in this area is restricted by the lack of effective excited-state gain processes. Herein, we originally proposed and demonstrated the cascaded occurrence of excited-state intramolecular proton transfer for constructing the completely new energy-level systems. Cascading by the first ultrafast proton transfer of <430 fs and the subsequent irreversible second proton transfer of ca. 1.6 ps, the stepwise proton transfer process favors the true six-level photophysical cycle, which supports efficient population inversion and thus NIR single-mode lasing at 854 nm. This work realizes longest wavelength beyond 850 nm of organic single-crystal lasing to date and originally exploits the cascaded excited-state molecular proton transfer energy-level systems for organic solid-state lasers.

10.
Acta Pharmacol Sin ; 41(11): 1377-1386, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32968208

RESUMO

The novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) and an ongoing severe pandemic. Curative drugs specific for COVID-19 are currently lacking. Chloroquine phosphate and its derivative hydroxychloroquine, which have been used in the treatment and prevention of malaria and autoimmune diseases for decades, were found to inhibit SARS-CoV-2 infection with high potency in vitro and have shown clinical and virologic benefits in COVID-19 patients. Therefore, chloroquine phosphate was first used in the treatment of COVID-19 in China. Later, under a limited emergency-use authorization from the FDA, hydroxychloroquine in combination with azithromycin was used to treat COVID-19 patients in the USA, although the mechanisms of the anti-COVID-19 effects remain unclear. Preliminary outcomes from clinical trials in several countries have generated controversial results. The desperation to control the pandemic overrode the concerns regarding the serious adverse effects of chloroquine derivatives and combination drugs, including lethal arrhythmias and cardiomyopathy. The risks of these treatments have become more complex as a result of findings that COVID-19 is actually a multisystem disease. While respiratory symptoms are the major clinical manifestations, cardiovascular abnormalities, including arrhythmias, myocarditis, heart failure, and ischemic stroke, have been reported in a significant number of COVID-19 patients. Patients with preexisting cardiovascular conditions (hypertension, arrhythmias, etc.) are at increased risk of severe COVID-19 and death. From pharmacological and cardiovascular perspectives, therefore, the treatment of COVID-19 with chloroquine and its derivatives should be systematically evaluated, and patients should be routinely monitored for cardiovascular conditions to prevent lethal adverse events.


Assuntos
Doenças Cardiovasculares/complicações , Cloroquina/análogos & derivados , Cloroquina/uso terapêutico , Infecções por Coronavirus/complicações , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/complicações , Pneumonia Viral/tratamento farmacológico , Antivirais/farmacologia , COVID-19 , Cloroquina/farmacologia , Humanos , Pandemias , Tratamento Farmacológico da COVID-19
11.
Biosci Biotechnol Biochem ; 84(9): 1788-1798, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32448038

RESUMO

Many phenolic compounds, derived from lignin during the pretreatment of lignocellulosic biomass, could obviously inhibit the activity of cellulolytic and hemicellulolytic enzymes. Acetosyringone (AS) is one of the phenolic compounds produced from lignin degradation. In this study, we investigated the inhibitory effects of AS on xylanase activity through kinetic experiments. The results showed that AS could obviously inhibit the activity of xylanase in a reversible and noncompetitive binding manner (up to 50% activity loss). Inhibitory kinetics and constants of xylanase on AS were conducted by the HCH-1 model (ß = 0.0090 ± 0.0009 mM-1). Furthermore, intrinsic and 8-anilino-1-naphthalenesulfonic (ANS)-binding fluorescence results showed that the tertiary structure of AS-mediated xylanase was altered. These findings provide new insights into the role of AS in xylanase activity. Our results also suggest that AS was an inhibitor of xylanase and targeting AS was a potential strategy to increase xylose production.


Assuntos
Acetofenonas/farmacologia , Endo-1,4-beta-Xilanases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Polissacarídeos/metabolismo , Hidrólise/efeitos dos fármacos , Cinética
12.
Pediatr Cardiol ; 41(8): 1594-1600, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32700035

RESUMO

Single ventricle (SV) physiology is associated with growth retardation in children. The nutritional status of pediatric patients with SV undergoing a bidirectional Glenn (BDG) procedure vitally affects the feasibility of the next operation stages. To explore the nutritional status and to identify specific anthropometric parameters relevant to short-term surgical outcomes in children with SV after the BDG procedure, this study included 151 patients who underwent the BDG procedure. Anthropometric assessments and Infant and Child Feeding Index (ICFI) scores were used to evaluate nutritional status. There was a significant statistical correlation between ICFI and malnutrition in both the height-for-age Z-score (HAZ) and weight-for-age Z-score (WAZ) groups (P < 0.05). The clinical data, including ventilation time, nosocomial infection presence, pressure injury presence, peritoneal dialysis status, and total intensive care unit days, after BDG surgery were significantly different among the HAZ groups (P < 0.05), while nosocomial infection was different among the WAZ groups (P < 0.05). Children after BDG procedure had a high incidence of malnutrition, in addition to disease factors, the type and frequency of dietary intake were also important factors leading to worse clinical outcomes during hospitalization. Therefore, it is vital to maintain an optimal nutritional status in infants with SV who are undergoing a series of surgical procedures.


Assuntos
Técnica de Fontan/métodos , Cardiopatias Congênitas/cirurgia , Ventrículos do Coração/anormalidades , Desnutrição/epidemiologia , Estado Nutricional , Antropometria , Peso Corporal , Pré-Escolar , Dieta , Feminino , Ventrículos do Coração/cirurgia , Hospitalização , Humanos , Lactente , Masculino , Inquéritos e Questionários
13.
J Am Chem Soc ; 141(42): 16743-16754, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31550879

RESUMO

Here we demonstrate that highly ß-selective glycosylation reactions can be achieved when the electronics of a sulfonyl chloride activator and the reactivity of a glycosyl donor hemiacetal are matched. While these reactions are compatible with the acid- and base-sensitive protecting groups that are commonly used in oligosaccharide synthesis, these protecting groups are not relied upon to control selectivity. Instead, ß-selectivity arises from the stereoinversion of an α-glycosyl arylsulfonate in an SN2-like mechanism. Our mechanistic proposal is supported by NMR studies, kinetic isotope effect (KIE) measurements, and DFT calculations.


Assuntos
Ácidos Sulfônicos/química , Teoria da Densidade Funcional , Glicosilação , Cinética , Modelos Moleculares , Conformação Molecular
14.
Neurochem Res ; 44(9): 2170-2181, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31420834

RESUMO

Acute inhalation of combustion smoke produces long-term neurologic deficits in survivors. To study the mechanisms that contribute to the development of neurologic deficits and identify targets for prevention, we developed a mouse model of acute inhalation of combustion smoke, which supports longitudinal investigation of mechanisms that underlie the smoke induced inimical sequelae in the brain. Using a transgenic mouse engineered to overexpress neuroglobin, a neuroprotective oxygen-binding globin protein, we previously demonstrated that elevated neuroglobin preserves mitochondrial respiration and attenuates formation of oxidative DNA damage in the mouse brain after smoke exposure. In the current study, we show that elevated neuronal neuroglobin attenuates the persistent inflammatory changes induced by smoke exposure in the mouse brain and mitigates concordant smoke-induced long-term neurobehavioral deficits. Specifically, we found that increases in hippocampal density of GFAP and Iba-1 positive cells that are detected post-smoke in wild-type mice are absent in the neuroglobin overexpressing transgenic (Ngb-tg) mice. Similarly, the smoke induced hippocampal myelin depletion is not observed in the Ngb-tg mice. Importantly, elevated neuroglobin alleviates behavioral and memory deficits that develop after acute smoke inhalation in the wild-type mice. Taken together, our findings suggest that the protective effects exerted by neuroglobin in the brains of smoke exposed mice afford protection from long-term neurologic sequelae of acute inhalation of combustion smoke. Our transgenic mouse provides a tool for assessing the potential of elevated neuroglobin as possible strategy for management of smoke inhalation injury.


Assuntos
Hipocampo/metabolismo , Inflamação/metabolismo , Neuroglobina/metabolismo , Animais , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/metabolismo , Expressão Gênica/efeitos dos fármacos , Hipocampo/patologia , Inflamação/induzido quimicamente , Aprendizagem/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurogênese/efeitos dos fármacos , Neuroglobina/genética , RNA Mensageiro/metabolismo , Fumaça
15.
Acta Pharmacol Sin ; 40(5): 589-598, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30030529

RESUMO

High-mobility group box 1 (HMGB1) exhibits various functions according to its subcellular location, which is finely conditioned by diverse post-translational modifications, such as acetylation. The nuclear HMGB1 may prevent from cardiac hypertrophy, whereas its exogenous protein is proven to induce hypertrophic response. This present study sought to investigate the regulatory relationships between poly(ADP-ribose) polymerase 1 (PARP1) and HMGB1 in the process of pathological myocardial hypertrophy. Primary-cultured neonatal rat cardiomyocytes (NRCMs) were respectively incubated with three cardiac hypertrophic stimulants, including angiotensin II (Ang II), phenylephrine (PE), and isoproterenol (ISO), and cell surface area and the mRNA expression of hypertrophic biomarkers were measured. the catalytic activity of PARP1 was remarkably enhanced, meanwhile HMGB1 excluded from the nucleus. PARP1 overexpression by infecting with adenovirus PARP1 (Ad-PARP1) promoted the nuclear export of HMGB1, facilitated its secretion outside the cell, aggravated cardiomyocyte hypertrophy, which could be alleviated by HMGB1 overexpression. PE treatment led to the similar results, while that effect was widely depressed by PARP1 silencing or its specific inhibitor AG14361. Moreover, SD rats were intraperitoneally injected with 3-aminobenzamide (3AB, 20 mg/kg every day, a well-established PARP1 inhibitor) 7 days after abdominal aortic constriction (AAC) surgery for 6 weeks, echocardiography and morphometry of the hearts were measured. Pre-treatment of 3AB relieved AAC-caused the translocation of nuclear HMGB1 protein, cardiac hypertrophy, and heart dysfunction. Our research offers a novel evidence that PARP1 combines with HMGB1 and accelerates its translocation from nucleus to cytoplasm, and the course finally causes cardiac hypertrophy.


Assuntos
Cardiomegalia/etiologia , Núcleo Celular/metabolismo , Proteína HMGB1/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Angiotensina II/farmacologia , Animais , Isoproterenol/farmacologia , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Fenilefrina/farmacologia , Ratos Sprague-Dawley
16.
Acta Pharmacol Sin ; 39(5): 802-824, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29698387

RESUMO

Salvia miltiorrhiza Burge (Danshen) is an eminent medicinal herb that possesses broad cardiovascular and cerebrovascular protective actions and has been used in Asian countries for many centuries. Accumulating evidence suggests that Danshen and its components prevent vascular diseases, in particular, atherosclerosis and cardiac diseases, including myocardial infarction, myocardial ischemia/reperfusion injury, arrhythmia, cardiac hypertrophy and cardiac fibrosis. The published literature indicates that lipophilic constituents (tanshinone I, tanshinone IIa, tanshinone IIb, cryptotanshinone, dihydrotanshinone, etc) as well as hydrophilic constituents (danshensu, salvianolic acid A and B, protocatechuic aldehyde, etc) contribute to the cardiovascular protective actions of Danshen, suggesting a potential synergism among these constituents. Herein, we provide a systematic up-to-date review on the cardiovascular actions and therapeutic potential of major pharmacologically active constituents of Danshen. These bioactive compounds will serve as excellent drug candidates in small-molecule cardiovascular drug discovery. This article also provides a scientific rationale for understanding the traditional use of Danshen in cardiovascular therapeutics.


Assuntos
Cardiotônicos/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Animais , Doenças Cardiovasculares/fisiopatologia , Sinergismo Farmacológico , Células Endoteliais/efeitos dos fármacos , Fibrinolíticos/uso terapêutico , Humanos , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Salvia miltiorrhiza
17.
Acta Pharmacol Sin ; 39(12): 1837-1846, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29991711

RESUMO

Vascular endothelial cell senescence is a leading cause of age-associated and vascular diseases. Mammalian target of rapamycin complex 2 (mTORC2) is a conserved serine/threonine (Ser/Thr) protein kinase that plays an important regulatory role in various cellular processes. However, its impact on endothelial senescence remains controversial. In this study we investigated the role and molecular mechanisms of mTORC2 in endothelial senescence. A replicative senescence model and H2O2-induced premature senescence model were established in primary cultured human umbilical vein endothelial cells (HUVECs). In these senescence models, the formation and activation of mTORC2 were significantly increased, evidenced by the increases in binding of Rictor (the essential component of mTORC2) to mTOR, phosphorylation of mTOR at Ser2481 and phosphorylation of Akt (the effector of mTORC2) at Ser473. Knockdown of Rictor or treatment with the Akt inhibitor MK-2206 attenuated senescence-associated ß-galactosidase (ß-gal) staining and expression of p53 and p21 proteins in the senescent endothelial cells, suggesting that mTORC2/Akt facilitates endothelial senescence. The effect of mTORC2/Akt on endothelial senescence was due to suppression of nuclear factor erythroid 2-related factor 2 (Nrf2) at the transcriptional level, since knockdown of Rictor reversed the reduction of Nrf2 mRNA expression in endothelial senescence. Furthermore, mTORC2 suppressed the expression of Nrf2 via the Akt/GSK-3ß/C/EBPα signaling pathway. These results suggest that the mTORC2/Akt/GSK-3ß/C/EBPα/Nrf2 signaling pathway is involved in both replicative and inducible endothelial senescence. The deleterious role of mTORC2 in endothelial cell senescence suggests therapeutic strategies (targeting mTORC2) for aging-associated diseases and vascular diseases.


Assuntos
Senescência Celular/fisiologia , Células Endoteliais/fisiologia , Alvo Mecanístico do Complexo 2 de Rapamicina/fisiologia , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia
18.
Angew Chem Int Ed Engl ; 57(35): 11300-11304, 2018 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-30117234

RESUMO

Anisotropic organic molecular construction and packing are crucial for the optoelectronic properties of organic crystals. Two-dimensional (2D) organic crystals with regular morphology and good photon confinement are potentially suitable for a chip-scale planar photonics system. Herein, through the bottom-up process, 2D halogen-bonded DPEpe-F4 DIB cocrystals were fabricated that exhibit an asymmetric optical waveguide with the optical-loss coefficients of RBackward =0.0346 dB µm-1 and RForward =0.0894 dB µm-1 along the [010] crystal direction, which can be attributed to the unidirectional total internal reflection caused by the anisotropic molecular packing mode. Based on this crystal direction-oriented asymmetric photon transport, these as-prepared 2D cocrystals have been demonstrated as a microscale optical logic gate with multiple input/out channels, which will offer potential applications as the 2D optical component for the integrated organic photonics.

19.
Small ; 13(19)2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28296188

RESUMO

Organic semiconductor micro-/nanocrystals with regular shapes have been demonstrated for many applications, such as organic field-effect transistors, organic waveguide devices, organic solid-state lasers, and therefore are inherently ideal building blocks for the key circuits in the next generation of miniaturized optoelectronics. In the study, blue-emissive organic molecules of 1,4-bis(2-methylstyryl)benzene (o-MSB) can assemble into rectangular microcrystals at a large scale via the room-temperature solution-exchange method. Because of the Förster resonance energy transfer, the energy of the absorbed photons by the host matrix organic molecules of o-MSB can directly transfer to the dopant organic molecules of tetracene or 1,2:8,9-dibenzopentacene (DBP), which then emit visible photons in different colors from blue to green, and to yellow. More impressively, by modulating the doping molar ratios of DBP to o-MSB, bright white-emissive organic microcrystals with well-preserved rectangular morphology can be successfully achieved with a low doping ratio of 1.5%. These self-assembled organic semiconductor microcrystals with multicolor emissions can be the white-light sources for the integrated optical circuits at micro-/nanoscale.

20.
Acta Pharmacol Sin ; 38(9): 1257-1268, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28649129

RESUMO

Phosphodiesterase-9A (PDE9A) expression is upregulated during cardiac hypertrophy and heart failure. Accumulating evidence suggests that PDE9A might be a promising therapeutic target for heart diseases. The present study sought to investigate the effects and underlying mechanisms of C33(S), a novel selective PDE9A inhibitor, on cardiac hypertrophy in vitro and in vivo. Treatment of neonatal rat cardiomyocytes (NRCMs) with PE (100 µmol/L) or ISO (1 µmol/L) induced cardiac hypertrophy characterized by significantly increased cell surface areas and increased expression of fetal genes (ANF and BNP). Furthermore, PE or ISO significantly increased the expression of PDE9A in the cells; whereas knockdown of PDE9A significantly alleviated PE-induced hypertrophic responses. Moreover, pretreatment with PDE9A inhibitor C33(S) (50 and 500 nmol/L) or PF-7943 (2 µmol/L) also alleviated the cardiac hypertrophic responses in PE-treated NRCMs. Abdominal aortic constriction (AAC)-induced cardiac hypertrophy and ISO-induced heart failure were established in SD rats. In ISO-treated rats, oral administration of C33(S) (9, 3, and 1 mg·kg-1·d-1, for 3 consecutive weeks) significantly increased fractional shortening (43.55%±3.98%, 54.79%±1.95%, 43.98%±7.96% vs 32.18%±6.28%), ejection fraction (72.97%±4.64%, 84.29%±1.56%, 73.41%±9.37% vs 49.17%±4.20%) and cardiac output (60.01±9.11, 69.40±11.63, 58.08±8.47 mL/min vs 48.97±2.11 mL/min) but decreased the left ventricular internal diameter, suggesting that the transition to heart failure was postponed by C33(S). We further revealed that C33(S) significantly elevated intracellular cGMP levels, phosphorylation of phospholamban (PLB) and expression of SERCA2a in PE-treated NRCMs in vitro and in ISO-induced heart failure model in vivo. Our results demonstrate that C33(S) effectively protects against cardiac hypertrophy and postpones the transition to heart failure, suggesting that it is a promising agent in the treatment of cardiac diseases.


Assuntos
3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , Cardiomegalia/tratamento farmacológico , GMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Animais , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Células Cultivadas , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Pirazóis/administração & dosagem , Pirazóis/química , Pirimidinas/administração & dosagem , Pirimidinas/química , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
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